How many Chemos can you have?

Random question.

But providing my mum gets through her current 6 cycles of GemCis Chemo and it does help in stablising or shrinking her Bladder Cancer Mets in her lungs, how soon would they start another treatment session? Is there a certain rest period of a few months inbetween? I would love her to just be able to have even a couple of months inbetween treatments & was thinking of booking a little weekend break somewhere nearby but don't know if this is realistic. Also, how long can you carry on having chemo for? - until it stops working? Does the NHS only give a certain amount and then thats it? I've been reading stories of people with Grade IV bladder cancer who have survived a few years and I wondered if they had chemo all of that time...

My mum is 79 but in reasonably good health all things considered. 

Just a few things that are spinning through my mind this morning whilst I was in a meeting... 

Love & hugs to everyone caring for their loved ones with cancer - it really doesn't ever leave your head does it!

Mandy